The aim of this project is to elucidate the structures of connective tissue proteoglycans with a view to understanding their varied but specific functions. Three general approaches are employed. Monoclonal antibodies to the proteoglycans are raised, characterized and then serve to identify specific types of proteoglycan, determine their distribution, interactions and some aspects of structure. Peptide sequencing studies are beginning to yield valuable information about the proteoglycan protein core and allied glycoproteins (e.g., link proteins). Thirdly, chemical cross linking studies will help determine, at the molecular level, the nature of proteoglycan interactions with other extracellular elements (e.g., collagen, elastin, matrix glycoproteins).